Solve whats in the parentheses first
5k+25+4<21+6k
5k+29<21+6k
plug in a number in k for both sides
5(1)+29<21+6(1)
5+29<21+6
34<27
5(2)+29<21+6(2)
10+29<21+12
39<33
so 5(k+5)+4 is greater than 21+6k
Let the cost of 1 notebook be x and the cost of 1 binder be y.
4 notebooks and 3 binders would cost 23.5
Therefore, 4x + 3y = 23.5 (1)
7 notebooks and 6 binders would cost 44.5
Therefore, 7x + 6y = 44.5 (2)
Multiply the first equation by 2.
8x + 6y = 47 (3)
(3) - (2) gives
x = 2.5
Substitute the value of x in (1), we get,
4(2.5) + 3y = 23.5
10 + 3y = 23.5
3y = 23.5 - 10
3y = 13.5
y = 13.5/3
y = 4.5
Hence, cost of 5 notebooks and 3 binders is:
5x + 3y = 5(2.5) + 3(4.5)
= 12.5 + 13.5
= 26
Hence, cost of 5 notebooks and 3 binders is $26.
900,000,000. move the decimal until you have a number between 1-10 so move it 8 times and you'll have 9×10^8
The answer would be a decimal so the answer is 7.4161984871.
